Drawing table attachment



Sept. 22, 1959 H. J, CIFREDO 2,904,926

DRAWING TABLE ATTACHMENT Filed Nov. 7, v 1957 2 SheetsSheet 1 INVENTOR.

HECTOR .l. CIFREDO 1% HT'TURNEY p 2 1959 v H. J. CIFREDO 2,904,926

DRAWING TABLE ATTACHMENT 2 Sheets-Sheet 2 Filed NOV. 7, 1957 INVENTOR. HECTOR J. CIFREDO HTTURNEY United States Patent 2,904,926 DRAWING TABLE ATTACHMENT Hector J. Cifredo, New York, N.Y.

Application November 7, 1957, Serial No. 694,988 1 Claim. (Cl. 45-131) This invention relates to drafting tables, and more particularly has reference to a drafting table constituting a unitary assembly adapted to facilitate the positioning of a sheet of drafting paper, and further adapted to facilitate the retention of said sheet in its assigned position.

One important object is to incorporate a suction head assembly in a drafting table work surface, which assembly will be so designed that a suction will be set up at the underside of a sheet of drafting paper, which suction will effectively hold the drafting paper in place without the necessity of tacks, tape, etc.

Another object is to provide in a drafting table means designed to permit drafting paper to be torn off to a selected size from a roll of the same, which roll will be conveniently located in front of the work surface.

Another object is to provide, in a drafting table, paperfeeding means that will include a cutting knife, along which a selected piece of drafting paper can be pulled for tearing of the same from the roll.

Another object is to form the suction head assembly as a unitary, frame-like structure, capable of being preassembled prior to its attachment to the working surface of the drafting table.

Another object is to so form the suction head assembly as to include therein a series of rectangularly spaced suction heads supported by the conduits in which airsuction occurs, so that said conduits discharge a framing or supporting function in respect to the suction heads.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings, and to the appended claim in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

Fig. 1 is a perspective view of a drafting table according to the present invention.

Fig. 2 is a vertical sectional view through the table, substantially on line 2-2 of Fig. 1.

Fig. 3 is an enlarged, fragmentary top plan view of a corner portion of the table, showing one of the suction heads. 7

Fig. 4 is a still further enlarged perspective view of one of the suction heads per se, suction tubes extending therefrom being illustrated fragmentarily.

Fig. 5 is a sectional view, enlarged above the scale of Fig. 3, taken substantially on line 5-5 of Fig. 3.

Fig. 6 is a fragmentary bottom view taken on the line A 6-6 of Fig. 2.

Fig. 7 is an enlarged fragmentary plan view of Fig. 1.

Fig. 8 is a sectional view taken on the line 88 of Fig. 7.

Referring to the drawings in detail, a fiat, horizontal, rectangular base plate 10 underlies along its front edge a vertical, rectangular support plate 12 coextensive in width with the base plate and having at its lower end, over its full width, an inwardly extending attaching flange 14 secured to the base plate by bolts 16. Bolts 16 extend into a floor surface S, thus anchoring base plate 10 to the floor surface at one side. Anchoring bolts 18, at the other side of the base plate, cooperate with the bolts 16 insecuring the same fixedly to the supporting surface.

A stool 20 includes a flat, circular seat 22, secured by bolts 24 to a flat, circular top flange 26 integrally or otherwise rigidly formed upon the larger upper end of a flared top portion 28 of a support bar or standard 30. Standard 30 in the illustrated example is compoundly curved, with its lower end offset toward the support plate 12, relative to seat 22. At its lower end bar 30 is integrally or otherwise rigidly formed with a flat base flange 32, fixedly secured by bolts 34 to the base plate 10.

A work support plate or table top 36 of flat, rectangular configuration is coextensive in width with support plate 12, and overlies base plate 10, said plate 36 being disposed in a plane inclined to a slight extent from the horizontal. Plate 36 declines in a direction from the support plate 12 towards the stool 20, so as to conveniently dispose the drafting paper or board so far as the worker is concerned.

A connector flange or support bracket 38 underlies the forward portion of plate 36, said flange 38 being of acuteangular crosssectional configuration, and including a depending portion 40 secured by bolts 42 to the upper portion of plate 12. Bolts 44 secure the inclined top portion 46 of the flange 40 to the front portion of the Work support plate 36.

To rigidify the connection of the work support plate to the support plate 12, there may also be provided a plurality of connecting screws 48 spaced uniformly across the width of. the work support plate 36.

Bracing plate 36 in its inclined position are identical, transversely spaced brace arms 50, disposed at an angle to the plane of the plate 12 and plate 36. The brace arms 50 at their lower ends have vertically depending extensions 52 secured by bolts 54 or the like to the respective side poitions of the plate 12, adjacent the lower end of said plate 12. At their other ends arms 50 have extensions 56, secured by bolts 58 to the work support plate 36, adjacent that end of the work support plate nearer stool 20. i

Projecting forwardly from the upper end of plate 12, in front of the plate 36, is an elongated container or housing 60 for a roll 62 of drafting paper which issues as a web 64. The container 60 is formed open at its upper end, and the open top of the container is normally closed by a cover 66, which may have a peripheral recess 68 receiving the top edge portion of container 60 for the purpose of frictionally engaging the cover in its closed position. f

Roll 62 is supported for free rotational movement through the provision of a core or shaft 70, on which the drafting paper is tightly wound. Core 70 at its opposite ends engages in vertical bearing slots or grooves 72 formed in the inner surfaces of the end walls 74 of container 6t). Slots 72 open upwardly, to permit insertion and removal of a roll.

Referring to Fig. 8 formed in lid or cover 66'is a longitudinal slot. 76, through which web'64- passes as it is unwound from roll 62. One wall.78- of slot 76is inclined slightly from the vertical, this being the outer wall of the slot. The inner wall 80 of the slot is inclined more steeply from the vertical with the inclination of wall 80 being opposite to that of wall. 78.

Formed in the top surface of lid 66 is a shallow, longitudinal depression 82 in which is engaged a cutter knife 84, secured fixedly within depression 82 through the provision of a series of screws '86 extending through openings of the knife into threaded recesses of the cover.

Knife 84 (see Fig. 7) has a cutting edge 88 which may be scalloped as shown in Fig. 7 to facilitate tearing of the web thereupon. The cutting edge projects into the slot 76, over approximately half of the slot as clearly shown in Fig. 8. 7

By reason of this arrangement and referring now to Fig. 1, one merely pulls the web 64 in the direction of the stool. When a selected amount of paper has been pulled through the slot, the paper is torn off along the cutter knife.

The paper is now ready to be properly positioned upon plate 36, in respect to a suction assembly generally designated at 90.

The suction assembly 90 includes rectangularly spaced, right-angular suction heads 92. These would underlie the corner portions of the sheet of drafting paper, when the drafting paper is properly positioned. The suction heads, as clearly shown in Figs. 4 and 5, have top walls 94 freely perforated as at 96, with the side and bottom walls of the suction heads being otherwise imperforate.

Projecting from opposite ends of each suction head are tubes 98, communicating with the interiors of the suction heads as clearly shown in Fig. 5. The several tubes 98 are arranged in a rectangular series as best shown in Fig. 6. As a result, since each tube communicates at its opposite ends with the suction heads, all the suction heads are connected in communication through the provision of the tubes. There is thus defined a suction assembly which is in the form of a rectangular, open frame, secured to the underside of the plate 36, the several corners of the frame being formed as suction heads freely perforated on their upper surfaces.

In this connection, the tubes are fixedly secured to the underside of plate 36 through the provision of clamps or saddles 100, there being a pair of saddles adjacent opposite ends of each head. The several heads are snugly fitted in right-angular openings 102 of the plate 36, with the top walls 94 flush with the top surface of the plate 36, as clearly shown in Fig. 5.

One of the tubes 96 is connected, by a fitting 10-4, to a suction line 106, which extends to the inlet 108 (see Fig. l) of a vacuum pump 110 which, in the illustrated example, is in the form of a suction fan, having an outlet to atmosphere designated at 112.

The suction fan 110 is mounted upon an angle bracket 114 secured by screws 116 to the inner surface of the support plate 12. Also fixedly mounted upon the brackets 114 is a drive motor 118, having a driving connection to the fan 110, said driving connection driving a belt 120.

The motor 118 is, of course, connectable to a source of electric power and in circuit with the motor is a switch 122 which, as shown, may be mounted upon the underside of plate 36, at one side of the plate.

In use, after the sheet of drafting paper has been torn 01f to the selected size, it is disposed over the suction heads, with the heads underlying the several corners of the sheet. Then, the switch 122 is operated to on position, so that the vacuum pump is placed in operation. Suction is created in line 106 and this in turn tends to create a vacuum within the several tubes, which in turn creates suction in the suction heads.

To replace the air drawn out of the suction heads, there is a tendency for air to move downwardly through the perforations 96. This, of course, causes the corner portions of the sheet of drafting paper to be pulled firmly against the suction heads with the several corners of the sheet adhering to the suction heads.

In this way, the necessity of tacks, pieces of masking tape, and other expedients often employed by draftsmen, is dispensed with.

Obviously, various changes might be made in the illustrated construction within the scope, of course, of the appended claims. One might, for example, vary the particular design of the stool and then again, one may vary support means 10, 12. One might even eliminate the base plate and use a different type of supporting frame for the plate 26. Still further, the suction assembly might be changed in a commercial embodiment, and it also follows that the use of a roll of drafting paper fed from a container might be dispensed with in some instances.

It is to be understood that a hand blower device may be used instead of a suction fan, for creating a suction when the plunger of the device is pulled in one direction and when the plunger is moved in the opposite direction, the air is forced into the suction heads 92 and the drawing paper may the be removed.

While I have illustrated and described the preferred embodiment of my invention, it is to be understood that I do not limit myself to the precise construction herein disclosed and that various changes and modifications may be made within the scope of the invention as defined in the appended claim.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent 1s:

A drafting table attachment comprising a support structure, a table top on said structure, an air suction head assembly in the table top for holding drafting paper to the table top responsive to the creation of suction in the suction head assembly, and means for creating suction within said suction head assembly, said suction head assembly including rectangularly spaced suction heads, each suction head having a perforated top wall through which air is drawn to hold the drafting paper against the surface of the table top said suction head assembly further including a rectangular series of connecting tubes, each connecting tube being in communication with an extending between adjacent suction heads, thus to provide a rectangular frame at the several corners of which the suction heads are disposed, the suction-creating means including a suction line connected in communication with one connecting tube, for creating suction simultaneously within all the suction heads and tubes responsive to the creation of suction in said line.

References Cited in the file of this patent UNITED STATES PATENTS 616,347 Oswald Dec. 20, 1898 1,288,607 Jobke Dec. 24, 1918 1,395,328 Adams Nov. 1, 1921 1,927,000 Keutfel Sept. 12, 1933 1,934,952 Shoemaker Nov. 14, 1933 2,015,368 Ryan Sept. 24, 1935 2,098,655 De Lisle Nov. 9, 1937 2,417,496 Huebner Mar. 18, 1947 2,492,528 Huebner Dec. 27, 1949 2,645,543 Mancini July 14, 1953 2,683,641 Larson July 13, 1954 2,689,411 Huck Sept. 21, 1954 2,695,208 Graham Nov. 23, 1954 

